Portable exercise equipment, in various forms, has been known for many years. One of the recently more popular types of portable exercise equipment are various types of portable dumbbells. It is often difficult to travel with conventional dumbbells as they are somewhat heavy, by design and necessity. Accordingly, many types of water fillable dumbbells have become more common recently in order to permit ready carrying of these dumbbells in a suitcase or the like, without taking up too much room or being overly heavy, especially for airline travel.
One significant problem with water fillable dumbbells is that of adjustability of weight in order to provide the user with a selection of weight values depending on the exercise that is being done.
One such patent that discloses a system for accurately indexing water fillable dumbbell so that various selected weights can be achieved can be found in U.S. Pat. No. 6,758,795 issued Jul. 6, 2004 to Barber, and entitled Adjustable Water-Fillable Exercise Weights. These exercise weights comprise a readily portable dumbbell or barbell for exercising and weight training, in which weight units on an elongate handle comprise front and rear end plates interconnected by a collapsable/expandable fluid receptacle in the form of a resilient bellows. The weight unit is lengthened and expanded in order to accommodate fluid being added, and is shortened and decreased in volume corresponding to the fluid being removed. Although it is possible to retain the weight unit at its maximum size for any amount of water contained therein, this is generally unacceptable as the water would slosh around during exercising, which is unacceptable because it would be distracting and also because the forces involved in the water sloshing around would interfere with proper exercising. A calibration means is provided for visually indicating the weight of the unit corresponding to the longitudinal spacing between the front and end plates of the unit. In a preferred embodiment, a visually readable measure of weight is provided by means for a graduated bar insert which extends slidably within the hollow handle of the dumbbell or barbell and moves there along with expansion or contraction of the water-filled bellows.
Although the water-fillable dumbbell disclosed in the Barber patent does work well, it has been found that it may not be cost effective to manufacture.
U.S. Pat. No. 5,626,543 issued May 6, 1997 to Chen, discloses a Bellows-Like Exerciser that includes a bellows and a pair of gripping units attached to the bellows. The bellows include an elongate wall body that is made from a compressible and expandable resilient material and which defines a sealed interior chamber therein. The wall body has a first end portion, a second end portion and plurality of pleated sections located between and formed integrally with the end portions thereof. The first end portion has a radially extending circular orifice which is formed through a wall thereof and which has a predetermined diameter for permitting air to enter into an exit from the interior chamber only via the orifice. The gripping units are respectively attached to the first and second end portions of the wall body such as the wall body can be compressed or stretched by applying a force on the first and second end portions so as to vary the volume of the chamber in the wall body, thereby enabling the user to achieve an alternate pull and push exercising effects on a user. This bellows-like exerciser does not have means to permit the bellows to be retained at a specific size or displacement.
It is an object of the present invention to provide a collapsible and expandible exercise weight.
It is another object of the present invention to provide a collapsible and expandible exercise weight having a bellows type peripheral wall.
It is a further object of the present invention to provide a collapsible and expandible exercise weight usable as part of an exercise dumbbell.